This study aimed to enhance acid production rate and yield of citrus vinegar, and improve the quality of liquid fermented with fruit juice. [ Method] The saccharification process of citrus vinegar was investigated pre...This study aimed to enhance acid production rate and yield of citrus vinegar, and improve the quality of liquid fermented with fruit juice. [ Method] The saccharification process of citrus vinegar was investigated preliminarily with fruit-grain mixed fermentation method using liquor starters as saccharif- erous agents. [Result] The results indicated that the optimal glutinous rice saccharification conditions were as follows： fruit-grain ratio 3： 1, Aspergillus niger- Monascus purpureus ratio 3： 1, saccharifieafion temperature 60℃, and saccharification time 2.5 h. Under the optimized saccharification conditions, reducing sugar content in saceharified glutinous rice reached 146.43 mg/ml; after fermentation, alcohol content in fermentation broth was 6%, amino nitrogen content was 0.44 mg/ml, and acid yield was 3.1 g/L. [ Conclusion] Citrus vinegar brewed based on the optimized technological conditions exhibited better sensory and physico-chemical properties than that brewed with pure juice.展开更多
Fermented tigernut milk (FTM) was prepared from three different varieties (fresh yellow, big and small dry brown) of tigernut (Cyperus esculenta) obtained from Bodija market, Ibadan, Oyo state. Fifty two microbial iso...Fermented tigernut milk (FTM) was prepared from three different varieties (fresh yellow, big and small dry brown) of tigernut (Cyperus esculenta) obtained from Bodija market, Ibadan, Oyo state. Fifty two microbial isolates were obtained from FTM at different fermentation times, 32 of which were on MRS agar, 12 on nutrient agar and 8 on malt extract agar. Lactic acid bacteria were identified as Lactobacillus plantarum (LP), Lactococcus lactis (LC), Lactobacillus brevis, Lactococcus cremoris, Lactobacillus bulgaricus and Lactococcus thermophilus (LT). The non-LAB identified includes E. coli, Bacillus species and Proteus species while the yeasts include Saccharomyces cerevisiae and Candida kefyr. Lactic acid bacteria were found to predominate the total microflora of the FTM with their count ranging between 2.0 × 104 cfu/ml to 2.0 × 108 cfu/ml. Microbiological examination revealed that the FTM was safe for consumption as non-LAB counts were below the limit of acceptance which is 2.0 × 105 cfu/ml for dairy milk by Codex Alimentarius Commission. The quantity of lactic acid produced by the LAB isolates ranged between 0.86 g/l - 2.86 g/l while that of hydrogen peroxide ranged between 0.16 g/l - 0.51 g/l. Starter cultures were selected based on predominance of isolate, physiological characteristics, quantity of lactic acid and hydrogen peroxide production. The tiger nut varieties were fermented with the following starter combinations LP, LP/LC, LP/LC/LT, LP/LT while the fifth was spontaneously fermented. The nutritional, chemical and sensory properties of the starter fermented tiger nut milk were evaluated. The highest protein content (24.80%) was obtained in FTM with mixed cultures of LP/LC/LT while the least (3.00%) was obtained in spontaneously fermented milk. There was a significant difference in the FTM varieties. The highest fat content (9.40%) was obtained in spontaneously fermented tiger nut milk while the least (3.40%) was found in FTM with mixed cultures of LP/LC/LT. Fermentation decreased the pH and increased the lactic acid of the starter developed FTM, while sensory evaluation test showed that the FTM with mixed cultures of LP/LC/LT was highly acceptable. In conclusion, an excellent and acceptable FTM can be produced using treatments which comprise of pasteurization at 90°?for 15 minutes, fermentation at 45℃?for 18 hours using mixed cultures of Lactobacillus plantarum, Lactococcus lactis and Lactococcus thermophilus.展开更多
将植物乳杆菌(Lactobacillus plantarum CD101)和模仿葡萄球菌(Staphylococcus simulans NJ201)作为功能性发酵剂接种发酵鱼肉香肠,并以自然发酵为对照,利用pH值、质构、色差、抗氧化能力、挥发性风味物质、游离氨基酸等指标,探究功能...将植物乳杆菌(Lactobacillus plantarum CD101)和模仿葡萄球菌(Staphylococcus simulans NJ201)作为功能性发酵剂接种发酵鱼肉香肠,并以自然发酵为对照,利用pH值、质构、色差、抗氧化能力、挥发性风味物质、游离氨基酸等指标,探究功能性发酵剂对发酵鱼肉香肠品质、风味及多肽抗氧化活性的影响。结果表明:接种功能性发酵剂能够使鱼肉香肠在发酵期间pH值迅速降低,具有更低的pH值,提高了香肠的稳定性和安全性;提高了香肠的硬度和咀嚼性、提升了亮度和色泽,使之拥有更好的品质;显著提高了香肠多肽对1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基以及羟自由基的清除率,有助于香肠多肽抗氧化活性的提升;增加了酮类、酯类等风味物质的含量,丰富了香肠的风味,使其有更强烈的甜味和果香;促进了香肠中游离氨基酸的释放,这些氨基酸有利于香肠营养性、抗氧化能力、风味的提升。展开更多
基金Supported by Project for Agro-scientific Research in the Public Interest of Science and Technology Department of Zhejiang Province(2012C22092)
文摘This study aimed to enhance acid production rate and yield of citrus vinegar, and improve the quality of liquid fermented with fruit juice. [ Method] The saccharification process of citrus vinegar was investigated preliminarily with fruit-grain mixed fermentation method using liquor starters as saccharif- erous agents. [Result] The results indicated that the optimal glutinous rice saccharification conditions were as follows： fruit-grain ratio 3： 1, Aspergillus niger- Monascus purpureus ratio 3： 1, saccharifieafion temperature 60℃, and saccharification time 2.5 h. Under the optimized saccharification conditions, reducing sugar content in saceharified glutinous rice reached 146.43 mg/ml; after fermentation, alcohol content in fermentation broth was 6%, amino nitrogen content was 0.44 mg/ml, and acid yield was 3.1 g/L. [ Conclusion] Citrus vinegar brewed based on the optimized technological conditions exhibited better sensory and physico-chemical properties than that brewed with pure juice.
文摘Fermented tigernut milk (FTM) was prepared from three different varieties (fresh yellow, big and small dry brown) of tigernut (Cyperus esculenta) obtained from Bodija market, Ibadan, Oyo state. Fifty two microbial isolates were obtained from FTM at different fermentation times, 32 of which were on MRS agar, 12 on nutrient agar and 8 on malt extract agar. Lactic acid bacteria were identified as Lactobacillus plantarum (LP), Lactococcus lactis (LC), Lactobacillus brevis, Lactococcus cremoris, Lactobacillus bulgaricus and Lactococcus thermophilus (LT). The non-LAB identified includes E. coli, Bacillus species and Proteus species while the yeasts include Saccharomyces cerevisiae and Candida kefyr. Lactic acid bacteria were found to predominate the total microflora of the FTM with their count ranging between 2.0 × 104 cfu/ml to 2.0 × 108 cfu/ml. Microbiological examination revealed that the FTM was safe for consumption as non-LAB counts were below the limit of acceptance which is 2.0 × 105 cfu/ml for dairy milk by Codex Alimentarius Commission. The quantity of lactic acid produced by the LAB isolates ranged between 0.86 g/l - 2.86 g/l while that of hydrogen peroxide ranged between 0.16 g/l - 0.51 g/l. Starter cultures were selected based on predominance of isolate, physiological characteristics, quantity of lactic acid and hydrogen peroxide production. The tiger nut varieties were fermented with the following starter combinations LP, LP/LC, LP/LC/LT, LP/LT while the fifth was spontaneously fermented. The nutritional, chemical and sensory properties of the starter fermented tiger nut milk were evaluated. The highest protein content (24.80%) was obtained in FTM with mixed cultures of LP/LC/LT while the least (3.00%) was obtained in spontaneously fermented milk. There was a significant difference in the FTM varieties. The highest fat content (9.40%) was obtained in spontaneously fermented tiger nut milk while the least (3.40%) was found in FTM with mixed cultures of LP/LC/LT. Fermentation decreased the pH and increased the lactic acid of the starter developed FTM, while sensory evaluation test showed that the FTM with mixed cultures of LP/LC/LT was highly acceptable. In conclusion, an excellent and acceptable FTM can be produced using treatments which comprise of pasteurization at 90°?for 15 minutes, fermentation at 45℃?for 18 hours using mixed cultures of Lactobacillus plantarum, Lactococcus lactis and Lactococcus thermophilus.
文摘将植物乳杆菌(Lactobacillus plantarum CD101)和模仿葡萄球菌(Staphylococcus simulans NJ201)作为功能性发酵剂接种发酵鱼肉香肠,并以自然发酵为对照,利用pH值、质构、色差、抗氧化能力、挥发性风味物质、游离氨基酸等指标,探究功能性发酵剂对发酵鱼肉香肠品质、风味及多肽抗氧化活性的影响。结果表明:接种功能性发酵剂能够使鱼肉香肠在发酵期间pH值迅速降低,具有更低的pH值,提高了香肠的稳定性和安全性;提高了香肠的硬度和咀嚼性、提升了亮度和色泽,使之拥有更好的品质;显著提高了香肠多肽对1,1-二苯基-2-三硝基苯肼自由基、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基以及羟自由基的清除率,有助于香肠多肽抗氧化活性的提升;增加了酮类、酯类等风味物质的含量,丰富了香肠的风味,使其有更强烈的甜味和果香;促进了香肠中游离氨基酸的释放,这些氨基酸有利于香肠营养性、抗氧化能力、风味的提升。
